1. Field of the Invention
The present invention relates to a multilayer film-coated member fabricated by forming a multilayer film on a substrate for abrasion-resistant members for cutting tools, molds and combustion engines or for members requiring heat resistance and abrasion resistance for airplanes, ground turbines, engines, gaskets, gears, pistons and others, and relates to a method for producing it.
2. Background Art
In cutting work for cutting steel material, a type of hardly-cuttable material, there may happen a phenomenon of adhesion of the steel material to the edges of the cutting tool used. Owing to the adhesion, the edges lose stability, and the tool life is extremely shortened. Many trials for solving the problems have heretofore been made. For preventing the adhesive phenomenon, it has heretofore been investigated to improve the lubricative characteristics of coating film and to use coating film having low affinity to the object to be worked. For example, in Patent Reference 1, it is proposed to improve the hardness and the lubricative characteristics a cutting tool of cemented carbide by coating it with a TiVCN film formed by adding V and C to a TiN film. In Patent Reference 2, proposed is a CrSiBN coating film, and this is improved over a Cr-base coating film having low affinity to iron-based steel material, in point of the lubricative characteristics and the hardness. In Patent Reference 3, proposed is a coating film having improved heat resistance and hardness and applicable to high-speed working.    Patent Reference 1: JP-A 2000-129463    Patent Reference 2: JP-A 2001-328008    Patent Reference 3: JP-A 2007-126714
The field of cutting work is grouped into a field of mold working and a field of parts working. In any field, heretofore, lead is added to steel material as an easily-cuttable ingredient therein; recently, however, lead is removed from many steel materials for reducing the environmental load. Accordingly, owing to the removal of the lead ingredient therefrom, the recent steel materials are hardly cuttable as objects to be worked. Further, in the recent mold working field, the users' needs are prolongation of mold life, and various elements are added to the steel material for mold so as to meet the needs of mold life prolongation. Accordingly, the material characteristics of steel material are improved, but on the contrary, the machinability thereof is worsened. In the field of parts working, especially for parts for combustion engines, the parts are desired to be resistant to high temperatures as the exhaust gas temperature rises from the viewpoint of mileage improvement. With that, materials resistant to high temperatures are selected; and use of Ti alloy and Ni-base ultra-heat-resistant alloy, which have not been used so much in the field, is increasing. The materials are hardly-cuttable materials and their machinability is extremely poor. The important factors are that they may readily adhere to cutting tools and the working heat increases owing to their poor thermal conductivity. One serious problem is that they may readily adhere to cutting tools. For preventing the adhesive phenomenon, it is said that improving the lubricative characteristics of coating film and using coating film with low affinity to objects to be worked may be effective; however, these depend on the compatibility between coating film and steel material, and therefore these may be ineffective for different steel materials. It has been confirmed that all the techniques in the above-mentioned patent references are effective for specific steel materials, but their effects could not be confirmed for various and different steel materials.